CO2 field experiment likely to cause “do-over” for climate models

I have two press releases here, one via EurekAlert, and one from Max Planck. Plus at the end a summary of points via WUWT regular Pierre Gosselin. First, a key point. You can see the CO2 respiration of the biosphere in the Mauna Loa CO2 record below:

CO2 Trend for Mauna Loa - note the dip in 2008 when global temperatures plummeted, and the step again from 2009 into 2010 when an El Nino occurred

Breath of the Earth: Cycling carbon through terrestrial ecosystems

New data on photosynthesis and respiration will improve models, researchers say

This release is available in Italian, German, Spanish, French, Chinese, and Japanese.

This is the Eddy-Flux-Tower in the Hainich National Park, Germany.


Two recent international studies are poised to change the way scientists view the crucial relationship between Earth’s climate and the carbon cycle. These reports explore the global photosynthesis and respiration rates—the planet’s deep “breaths” of carbon dioxide, in and out—and researchers say that the new findings will be used to update and improve upon traditional models that couple together climate and carbon.

The two reports will be published online by the journal Science at the Science Express Web site at 6 p.m., US ET, Monday, 5 July. Science is published by AAAS, the nonprofit science society.

Christian Beer from the Max Planck Institute for Biogeochemistry in Jena, Germany, along with colleagues from 10 other countries around the world, first take a look at Earth’s Gross Primary Production, or GPP, which represents the total amount of carbon dioxide that terrestrial plants breathe in through photosynthesis each year. With a novel combination of observations and modeling, they estimate the total amount of carbon that the world’s plant life inhales annually is 123 billion metric tons.

Then, Miguel Mahecha, also from the Max Planck Institute for Biogeochemistry, and another international team of researchers settle a long-standing debate over the effects of short-term variations in air temperature on ecosystem respiration, or the Earth’s exhalation of carbon dioxide back into the atmosphere. They show that the sensitivity of ecosystem respiration to short-term variations in temperature is similar around the world. The researchers also suggest that factors other than temperature, such as the slow, ongoing transformations of carbon in the soil and water availability, appear to play crucial roles in long-term ecosystem carbon balances.

Together, these findings shed more light on the global cycle of carbon into and out of the atmosphere and how those processes are coupled with Earth’s ever-changing climate. The researchers analyzed vast amounts of climate and carbon data from around the world, and they say their results should help to improve the validity of predictive models and help resolve how climate change might affect the carbon cycle—and our world—in the future.

“An understanding of the factors that control the GPP of various terrestrial ecosystems is important because we humans make use of many ecosystem services, such as wood, fiber, and food,” said Beer. “Additionally, such an understanding is important in the context of climate change as a consequence of carbon dioxide emissions from burning fossil fuels because vegetation greatly modulates the land-atmosphere exchanges of greenhouse gases, water, and carbon dioxide…”

In their report, Beer and his colleagues pooled large amounts of data from FLUXNET, an international initiative established more than 10 years ago to monitor exchanges of carbon dioxide between Earth’s ecosystems and the atmosphere, with remote sensing and climate data from around the world to calculate the spatial distribution of mean annual GPP between 1998 and 2006.

This is a view of the tropical forest in Ghana from the top of a flux tower.

The researchers highlight the fact that uptake of carbon dioxide is most pronounced in the planet’s tropical forests, which are responsible for a full 34 percent of the inhalation of carbon dioxide from the atmosphere. Savannas then account for 26 percent of the global uptake, although the researchers note that savannas also occupy about twice as much surface area as tropical forests.

Precipitation also plays a significant role in determining the gross global carbon dioxide uptake, the researchers found. They suggest that rainfall has a significant influence on the amount of carbon that plants utilize for photosynthesis on more than 40 percent of vegetated lands, a discovery that stresses the importance of water availability for food security. According to the study, climate models often show great variation, and some of them overestimate the influence of rainfall on global carbon dioxide uptake.

“We reached a milestone with this paper by using plenty of data from FLUXNET in addition to remote sensing and climate reanalysis,” Beer said. “With our estimation of global GPP, we can do two things—compare our results with [Earth system] process models and further analyze the correlation between GPP and climate.”

In the second study, Mahecha and his team of researchers also relied on the global collaboration within the FLUXNET network during their investigation of ecosystems’ sensitivity to air temperature. Compiling and analyzing data from 60 different FLUXNET sites, these researchers found that the respiratory sensitivity to temperature of the world’s ecosystems, commonly referred to as Q10, is actually quite set in stone—and that the Q10 value is independent of the average local temperature and of the specific ecosystem conditions.

For years, experts have debated the effect that air temperature has on global respiration, or the collective metabolic processes of organisms that return carbon dioxide to the atmosphere from Earth’s surface. Most empirical studies suggest that such ecosystem respiration around the world is highly sensitive to increasing temperatures, while the majority of predictive models suggest otherwise. Scientists say that global air temperatures may rise due to the presence of heat-trapping carbon dioxide from the burning of fossil fuels. But, this new result suggests that the temperature sensitivity of the natural exhalation of carbon dioxide from ecosystems has been overestimated and should be reevaluated.

This latest study, in settling the controversy, suggests that previous field studies failed to disentangle processes acting on different time-scales. Mahecha and his team considered the processes of the 60 different ecosystems on the exact same time-scale in order to nail the global mean Q10 down to a value of 1.4. Their new, standard value for various ecosystems’ sensitivity to air temperature suggests a less pronounced short-term climate-carbon feedback compared to previous estimates.

“Our key finding is that the short-term temperature sensitivity of ecosystem respiration to air temperature is converging to a single, global value,” Mahecha said. “Contrary to previous studies, we show that the sensitivity of ecosystem respiration to temperature variations seems to be independent from external factors and constant across ecosystems. In other words, we found a general relationship between variation in temperature and ecosystem respiration… Our findings reconcile the apparent contradictions of modeling and field studies.”

In the future, these two separate studies should allow for more precise predictions of how Earth’s warming climate will affect the exchange of carbon between our ecosystems and the atmosphere—and vice versa. They provide scientists with important tools for better understanding the world’s ecosystems and how the human race continues to influence and alter them.

###

The report by Beer et al. was funded by CarboEuropeIP, FAO-GTOS-TCO, iLEAPS, Max Planck Institute for Biogeochemistry, National Science Foundation, University of Tuscia, Université Laval, Environment Canada, and the U.S. Department of Energy.

The report by Mahecha et al. was funded by CarboEuropeIP, FAO-GTOS-TCO, iLEAPS, Max Planck Institute for Biogeochemistry, National Science Foundation, University of Tuscia, the U.S. Department of Energy, and grants from the European Research Council, the European Commission project CARBO-Extreme, and the Max Planck Society.

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Here’s the Press Release from the Max Planck Institute:

A new balance for the global carbon balance

Researchers determine how rates of photosynthesis and ecosystem respiration depend on the climate in order to obtain a better assessment of the consequences of climate change

Climate predictions could become more accurate and more reliable in the future – thanks to new findings on the role of terrestrial ecosystems in the global carbon cycle. International teams of researchers headed by the Max Planck Institute for Biogeochemistry in Jena now present comprehensive data analyses in two related studies. The analyses also lead to more precise estimates of how the ecosystems could react to climate change. In most ecosystems, the photosynthesis rate at which plants fix carbon dioxide from the atmosphere changes relatively little as temperature varies. Over 40 percent of the Earth’s vegetated surface reacts very sensitively to changes in the amount of precipitation, however. The respiration of the ecosystems, when flora and fauna release carbon dioxide, also increases to a lesser extent than has recently often been assumed when the temperature rises. Moreover, this temperature dependence is the same all over the world – even in ecosystems as different as the tropical savannah and the Finnish needleleaf forest, for example. (Science Express, July 5, 2010)

Fig. 1: Countless measurement stations (red) around the globe record the exchange of carbon dioxide and water in different ecosystems.

Image: Ulrich Weber, MPI for Biogeochemistry

The climate is quite temperamental: countless factors are involved and many feedback mechanisms enhance effects such as the anthropogenic greenhouse effect. This makes it difficult to make predictions, especially as many processes in the Earth system are still not completely understood. More light is now being shed on the part played by terrestrial ecosystems in the global carbon cycle. This applies to the role of photosynthesis, whereby plants fix carbon dioxide, as well as the process of respiration, during which plants release carbon dioxide once again. The scientists are thus making an important contribution to understanding how the global carbon cycle reacts to global warming and climate change. “Our results suggest that the availability of water, in particular, plays a decisive role for the carbon cycle in ecosystems. It is often more important than temperature,” says Markus Reichstein, a scientist at the Max Planck Institute for Biogeochemistry who has investigated these issues together with his colleagues and two international teams.

In one of the current studies, the researchers involved in the Fluxnet initiative measured how the respiration of ecosystems reacts to short-term variations in temperature at 60 stations spread across the globe. They found that the rate at which plants and microorganisms convert sugar into carbon dioxide does not even double when the temperature increases by ten degrees from one week to the next, for example. “With the aid of suitable models it is then possible to calculate how climate change could affect the respiration of the ecosystems and the global carbon cycle,” says Markus Reichstein.

Some earlier investigations at the ecosystem level resulted in threefold to fourfold accelerations, which would enhance the greenhouse effect. It was not possible to reconcile these data with global models and atmospheric measurements of carbon dioxide concentrations and their seasonal variations, however. “We can now settle obvious contradictions between experimental and theoretical studies,” says Miguel Mahecha, who played a crucial role in coordinating and evaluating the new measurements on ecosystem respiration. His colleague Markus Reichstein adds: “Particularly alarmist scenarios for the feedback between global warming and ecosystem respiration thus prove to be unrealistic.”

These measurements also contradict a further assumption which earlier investigations seemed to suggest: that the respiration of the ecosystems in the tropics and temperate latitudes is influenced to a lesser degree by temperature than at higher latitudes. As the Jena scientists have now discovered, the respiration of very different ecosystems intensifies to the same extent when it becomes hotter. The factor which determines the acceleration of the respiration thus obviously does not depend on the local temperature conditions and the specific characteristics of an ecosystem. “We were very surprised that different ecosystems react relatively uniformly to temperature variations,” says Miguel Mahecha. “After all, for example, we analysed savannahs, tropical rain forests, and also central European broadleaf and needleleaf forests and agricultural ecosystems.”

Fig. 2: Anemometers measure the wind speed ten times per second over leaf canopies and grasslands. With the movement of the air, gases such as carbon dioxide are exchanged between ecosystems and the atmosphere.

Image: MPI for Biogeochemistry

Climate researchers must now examine how the new findings affect the predictions for the carbon dioxide balance and climate change. “It is still not possible to predict whether this attenuates the positive feedback between carbon dioxide concentration and temperature,” says Markus Reichstein. “The study shows very clearly that we do not yet have a good understanding of the global biogeochemichal cycles and their importance for long-term developments.”

The researchers want to change this with their investigation of the rate of photosynthesis. According to this, the terrestrial ecosystems store 123 billion tonnes of carbon dioxide annually. “Although a similar value had been assumed before, it was only an hypothetical estimate,” says Christian Beer, who was in charge of the study. Sixty percent of the carbon dioxide which plants globally take up from the atmosphere is swallowed up by the tropical rain forests and savannahs. The savannahs owe their comparatively important role to the huge area which they cover. The rain forests, in contrast, take up particularly large amounts of carbon dioxide over relatively small areas in order to produce biomass.

The global analysis has also enabled the researchers to establish that the amount of carbon dioxide which is fixed by photosynthesis in leaves is influenced by different climatic factors in different vegetation zones. Sometimes the temperature plays a more important role, sometimes the intensity of the solar radiation, and sometimes the amount of water which the plants can take up from the ground.

From a global point of view, however, water is the factor which has the strongest effect: over 40 percent of Earth’s vegetated surface plants photosynthesize more when the supply of water increases, and less during droughts. In temperate grasslands and shrublands, the amount of carbon dioxide which plants fix as sugar depends to 69 percent on their water supply, in the tropical rain forest this figure is only 29 percent. The researchers call the amount of carbon dioxide which ecosystems annually take up primary production. “We were surprised to find that the primary production in the tropics is not so strongly dependent on the amount of rain,” says Markus Reichstein. “Here, too, we need to therefore critically scrutinize the forecasts of some climate models which predict the Amazon will die as the world gets drier.”

The data forming the basis of the two reports now published originate from an international network of over 250 measuring stations which undertake long-term observations in different ecosystems across the world. Teams of researchers have high measurement towers above grasslands or forests to record the water and carbon dioxide concentrations in the air and the wind turbulences all over the world. This enables them to calculate how much carbon dioxide is taken up and released by a certain ecosystem. They relate these values to the local climate and divide the Earth’s surface into quadrants measuring 50 by 50 kilometres. The researchers derive the global primary production by using satellite data to extrapolate the photosynthesis rates of the individual ecosystems. The satellites measure how much light energy the vegetated surface of the Earth absorbs on a global basis. Until now, climate researchers have extrapolated the interplay of climate and photosynthesis or ecosystem respiration on the basis of hypotheses.

The new Fluxnet initiative, which Markus Reichstein and colleagues from Italy and North America initiated, brings together the results of the global measurements for the first time. “We are gaining new insights into Earth’s climate system because various research groups are prepared to disclose their data,” says Reichstein. “The current studies, in particular, prove the added value of long-term observations of the Earth system for research. They help to reduce the uncertainty of current climate predictions and exclude some model predictions.”

[JM / PH]

Related links:

[1] Fluxnet Initiative

Original work:

Miguel D. Mahecha, Markus Reichstein, Nuno Carvalhais, Gitta Lasslop, Holger Lange, Sonia I. Seneviratne, Rodrigo Vargas, Christof Ammann, M. Altaf Arain, Alessandro Cescatti, Ivan A. Janssens, Mirco Migliavacca, Leonardo Montagnani, Andrew D. Richardson
Global Convergence in the Temperature Sensitivity of Respiration at Ecosystem Level
Science Express online, July 5, 2010 | http://dx.doi.org/10.1126/science.1189587

Christian Beer, Markus Reichstein, Enrico Tomelleri, Philippe Ciais, Martin Jung, Nuno Carvalhais, Christian Rödenbeck, M. Altaf Arain, Dennis Baldocchi, Gordon B. Bonan, Alberte Bondeau, Alessandro Cescatti, Gitta Lasslop, Anders Lindroth, Mark Lomas, Sebastiaan Luyssaert, Hank Margolis, Keith W. Oleson, Olivier Roupsard, Elmar Veenendaal, Nicolas Viovy, Christopher Williams, F. Ian Woodward, Dario Papale
Terrestrial Gross Carbon Dioxide Uptake: Global Distribution and Covariation with Climate

Science Express online, July 5, 2010 | http://dx.doi.org/10.1126/science.1184984

Max Planck Society
for the Advancement of Science
Press and Public Relations Department

PDF (300 KB)

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Here is a summary of key points via Pierre Gosselin:

1. In most ecosystems, the photosynthesis rate at which plants fix carbon dioxide from the atmosphere changes relatively little as the temperature varies.

2. The respiration of the ecosystems, when flora and fauna release carbon dioxide again, also increases to a lesser extent than has recently often been assumed when the temperature rises.

3. Moreover, this temperature dependence is the same all over the world – even in ecosystems as different as the tropical savannah and the Finnish needleleaf forest.

4. The climate is quite temperamental: countless factors are involved and many feedback mechanisms enhance effects such as the anthropogenic greenhouse effect. This makes it difficult to make predictions, especially as many processes in the Earth system are still not completely understood.

5. Results suggest that the availability of water, in particular, plays a decisive role for the carbon cycle in ecosystems. It is often more important than temperature.

6. Particularly alarmist scenarios for the feedback between global warming and ecosystem respiration thus prove to be unrealistic.”

7. The factor which determines the acceleration of the respiration thus obviously does not depend on the local temperature conditions and the specific characteristics of an ecosystem. “We were very surprised that different ecosystems react relatively uniformly to temperature variations.”

8. “It is still not possible to predict whether this attenuates the positive feedback between carbon dioxide concentration and temperature,” says Markus Reichstein. “The study shows very clearly that we do not yet have a good understanding of the global material cycles and their importance for long-term developments.”

9. “We were surprised to find that the primary production in the tropics is not so strongly dependent on the amount of rain,” says Markus Reichstein. “Here, too, we therefore need to critically scrutinize the forecasts of some climate models which predict the Amazon will die as the world gets drier.”

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79 thoughts on “CO2 field experiment likely to cause “do-over” for climate models

  1. The view from the top of the Flux tower in Ghana….looks like the view from the sentry tower on the moon of Yavin 4.

  2. As the level of CO2 rises, the need for water is lower.
    A plant needs water, light, CO2 and plant food.

    I laugh when they say it is getting hotter. If it is, that has to mean more ocean evaporation. Where will that evaporated water go if the amazon rainfall is predicted to drop dramatically?

  3. I see some sort of Möbius loop within the logic of the effects of rainfall/water.
    Did I get that right ?

  4. “Countless measurement stations (red) around the globe record the exchange of carbon dioxide and water in different ecosystems.”

    Have these scientists forgotten really basic stuff, like how to count?

    Or don’t they have a model that can give them the answer, so they assume it’s “countless”?

  5. So, if a brown lawn is watered it will take up more CO2 and get green? Over a temperature range of 45f to 105f? Wow.

  6. The main findings of this valuable, detailled scientific study seems to support the “sceptics'” view. Amazing what you find when you do science thoroughly, rather than simply feed fodder into super-computers!

  7. Do these guys, no matter how important and famous their institutions are (or rather were), prepare their breakfasts using hairdryers?. How does the air heat the oceans?
    (BTW don’t forget hairdryers must be plugged into a power source).

  8. What Douglas said. ditto

    “Douglas DC says:
    July 6, 2010 at 8:04 am
    In other words:” We have no bloody idea of what is really going on.”

  9. The IPCC contends that doubling the co2 concentration will cause a forcing of 3 to 6 degrees. Unfortunately they seem to be better at fudging data than applying physics. Their standard calculation is shown below.

    ∆T=4.7ln(c/co)=4.7ln(836/368)=4.7*.69=3.2Deg C

    However, H20 also absorbs 15 micron radiation. Since water vapor concentration is 1 to 4% of the near earth atmosphere , it would be more accurate to include all gasses that absorb 15 micron radiation. To be clear, c should include 10000ppm water vapor plus 836 ppm co2, and co should be 10000 ppm water vapor plus 386 ppm co2.

    ∆T=4.7*ln(10836/10386) = 4.7*.044 = .2 degrees C

    I can live with that.

  10. No sign of a big oil sponsor on the Max Planck Society website. Surely some mistake there? Maybe they missed it off in anticipation of the trolls…

    /sarc

  11. “I have studied the climate models and I know what they can do. The models solve the equations of fluid dynamics, and they do a very good job of describing the fluid motions of the atmosphere and the oceans. They do a very poor job of describing the clouds, the dust, the chemistry, and the biology of fields and farms and forests,”

    Freeman Dyson

  12. Henry chance says:
    July 6, 2010 at 7:45 am (Edit)

    As the level of CO2 rises, the need for water is lower.
    A plant needs water, light, CO2 and plant food.

    I laugh when they say it is getting hotter. If it is, that has to mean more ocean evaporation. Where will that evaporated water go if the amazon rainfall is predicted to drop dramatically?

    When the sun was making things hotter in the last half of the C20th, cloud was reduced, possibly due to the Svensmark effect. The reduced back radiation from reduced night-time cloud would probably more than offset increased evaporation from a sea surface 0.4C warmer than before.

    The Earth would compensate by taking the jet streams polewards I think.

  13. I have a question for someone who understands the land based carbon cycle better than I do.

    In a tropical forest, the plants take in carbon dioxide, water, and sunlight. They make cellulose and sugar and starch and it looks like a tree or a fern. After a few centuries, does the elevation continue to increase as carbon, in one form or another, builds up? Or does the amount of incoming CO2 settle into equilibrium equal the amount of outgoing CO2 as the dead plant matter decays?

    There seems to be an assumption here that a mature forest can somehow sequester an essentially infinite amount of matter, or am I missing something?

    It makes sense to me that CO2 absorbed into oceans and lakes can combine into carbonates or sediments that are more or less permanent. How does this work on land?

  14. I think nature’s feedback mechanisms are underestimated and even less understood. The climate is remarkably stable. Think about it, it has been stable enough to keep complex animals alive for a few 100 million years. In this time there have been no runaway climate changes, though the variables (such as CO2) have changed. If it hadn’t been this stable, we wouldn’t be around to study it. So I think it would be more fitting to speak of anthropic climate change rather than of anthropogenic climate change. Ref http://en.wikipedia.org/wiki/Anthropic_principle

  15. After reading this I just sense as a layman that the eventual winners (when science eventually prevail) will be people like Dr Roy Spencer and Prof. Richard Lindzen and their 20% effect of CO2 on global temperatures. So of the 0.6C increase over the last century or so consists probably of max. 0.15C CO2 effect and the rest of all other natural factors plus “adjustments”.

  16. cagw_skeptic99 says:
    July 6, 2010 at 9:30 am
    “[…]
    It makes sense to me that CO2 absorbed into oceans and lakes can combine into carbonates or sediments that are more or less permanent. How does this work on land?”

    The sediments are the product of erosion; erosion carries weathered rock debris, dead plant material etc. into rivers and oceans. How much this is i don’t know, but looking at river deltas of the Mississippi or the Ganges would indicate it’s massive.

  17. “In most ecosystems, the photosynthesis rate at which plants fix carbon dioxide from the atmosphere changes relatively little as temperature varies.”

    Hmm, photosynthesis rate should be directly related to plant growth, right? If water is the critical growth factor, and not temperature, how can they be using tree rings as thermometers?

  18. So, what is the “half-life” of CO2 in the athmosphere, then?

    Who is responsible for adding these Scientists names to the Blacklist?

    Where-ever you are; Hurry!

    Otherwise you will risk more papers from these dudes!

  19. The only thing settled about AGW is the dust in the skulls of the ‘X-perts’ who put the Global Warming data and reports together. It seems the first to publish are truly the last to know.

  20. This research beautifully destroys one foundation of the catastrophist’s fantasies: That an increase in temperature will reduce the photosynthetic capabilities of vegetation severely, leading to a much higher accumulation of CO2.

    Now they have two possibilities: Admit that catastrophic warming isn’t likely, or find a different candidate mechanism for the catastrophic scenario.

    (I’m using the term catastrophist to distinguish believers in catastrophic warming from moderate warmers. Which brings us to the interesting question of where western governments – Merkel et.al. stand on this issue. Even though Merkel might go the way of the Brown sometime soon now.)

  21. John W.
    I’d say the MPI is in general warmist as a whole, but are ready to change their minds as the science comes in. It is, after all, a worldclass organisation.
    Our sceptic views are also not rock solid. I think it’ll take another 10 or 20 years before we get a good idea as to how much of an impact our emissions really do have on the climate (I suspect it won’t be that much, though).

  22. Maybe a clearer way to state my question is this: Why so much focus on the land based CO2 cycle? Can there really be a material difference in the amount of land based CO2 contained in the flora of the earth from say, one decade to the next? More CO2 means more vigorous growth and an increase in the total plant matter, but then won’t the earth again reach equilibrium with respect to land based CO2 sequestered in plant material?

    It seems to me that those curious about how atmospheric CO2 concentrations will change should be focused on the oceanic carbon cycle. Maybe this is harder to measure or doesn’t contribute in the politically correct direction?

  23. cagw_skeptic99 says:
    July 6, 2010 at 10:26 am
    “[…]
    It seems to me that those curious about how atmospheric CO2 concentrations will change should be focused on the oceanic carbon cycle. Maybe this is harder to measure or doesn’t contribute in the politically correct direction?”

    I think the efforts to measure the effect of temperature increase on photosynthesis were done because of concern that the CO2 uptake would drop, which would indeed have been a catastrophe for the land-based biosphere and for food production. So it was a valid concern and urgent enough to get funded.

  24. “Our key finding is that the short-term temperature sensitivity of ecosystem respiration to air temperature is converging to a single, global value,” Mahecha said. “Contrary to previous studies, we show that the sensitivity of ecosystem respiration to temperature variations seems to be independent from external factors and constant across ecosystems. In other words, we found a general relationship between variation in temperature and ecosystem respiration… Our findings reconcile the apparent contradictions of modeling and field studies.”

    So what caused the great greening of the globe over the last few decades if it’s constant. There was a WUWT post with before and after satellite pictures showing this “greening” effect but I can’t seem to find it in searches. Think it was titled “The greening of the world” or “The greening of the globe”, something like that and was some 5-9 months ago at least. Anyone remember that post?

  25. I wonder if this impacts the results of GCMs?
    Time to ask some questions of gavin at RC.
    I’ll suggest that folks go to every warmista site on the net and just ask the question.
    Will these result require changes to GCMs? or not? will those changes get implemented before Ar5?

  26. From point 4 in Pierre Gosselin’s summary above:

    The climate is quite temperamental: countless factors are involved and many feedback mechanisms enhance effects such as the anthropogenic greenhouse effect.

    My emphasis. Always, always, countless factors ENHANCE AGW! Very disappointing.

  27. Re DirkH:

    “I think the efforts to measure the effect of temperature increase on photosynthesis were done because of concern that the CO2 uptake would drop, which would indeed have been a catastrophe for the land-based biosphere and for food production. So it was a valid concern and urgent enough to get funded.”

    There are biospheres that range from below freezing to well over 100F/38C. My own little back yard vegetable garden experiences these extremes in Virginia, USA. Water and sunlight produce green material, and warmer temperatures produce green material faster than colder ones do unless I fail to provide enough water when it is hot.

    I guess I go with some above who said: Duh? Can I express a concern that the earth’s orientation towards the sun might be changing and get funding to see what difference that would make? If the sun came up in the north and set in the south there would surely be changes in agriculture. Most anyone who actually puts seeds in the ground and tends to them would confirm that most plants grow faster when it is warmer, up to some tolerance point for some plants that don’t grow well in hot weather (lettuce and spinach bolt to seed, for example).

    I guess I am just not well enough educated in the climate sciences or sophisticated enough to grasp the basis for the concern.

  28. I enjoy reading the results of these incredibly (no doubt) expensive and time consuming studies because they reassure me that what I was taught in high school was in fact for the most part true. That is, the plant world adapted to large temperature variations in order to survive. Since photosynthesis is a biological process that is rather unaffected by temperature changes and since planet earth experiences a wide range of temperature variation (diurnal and annual), photosynthesis was the evolutionary winner among all the other possible ways to survive. Having “chosen” photosynthesis as the best way to handle large temperature variations, evolution turned to the next greatest challenge for plant life which is to find and be able to uptake water. Since water supply variations are common, the greatest variety of evolution in plant lifeforms is expressed in the plants ability to adapt and handle those water supply variations. This study is yet another demonstration of the validity of the evolutionary process.

  29. Be curious. Be open.
    Measure what happens.
    Publish results and methods.
    Stay away from anything “settled”.
    That’s what real science is all about.
    Good job done in Jena. Weiter so.

  30. There you go…. finally something that makes some science sense.

    … says Markus Reichstein. “Here, too, we need to therefore critically scrutinize the forecasts of some climate models which predict the Amazon will die as the world gets drier.”

    So a warmer globe by a few tenths of a degree (if it stays) means a wetter globe by increased the evaporation and therefore increase the rainfall and allow plants to fix more carbon. Now that’s properly a better science suspicion, broken GCMs (global climate computer models), not broken chemistry, physics, nad science in general.

  31. Looks like somewhat of an upset for the alarmist applecart. Not likely to warm the cockles of the hearts of the dedicated carbon-traders, is it?!

    Meanwhile, over at RC, I see that in their attempts to overcome the “problem in communicating the science to the public”, someone has devised a “simple recipe” that could not have been made more mind-numbingly, eye-glazingly complex to the casual reader if they tried. Yet I can read and understand the above articles with no difficulty. When will they ever learn, eh?!

    It will be interesting to see how long it takes before the dedicated alarmists roll-out the usual spin … “this does not affect the soundness of the underlying science … everything’s happening faster than we thought and we must act now”.

  32. latitude says:
    July 6, 2010 at 9:05 am
    What Douglas said. ditto

    “Douglas DC says:
    July 6, 2010 at 8:04 am
    In other words:” We have no bloody idea of what is really going on.”

    And we also know and accept that we don’t know – much or enough – thanks to that weird little “sceptic” feature of…er…our pre-Postmodern individual critical thought processes, which – like the pre-Postnormal Scientific Method’s incorportation of open access to the “materials and methods” involved in any truely Scientific study or conclusion, so that everyone who wants to can evaluate the study or conclusion, too – always asks, “What’s wrong with it?”

    Ah, but Armchair Science, now becoming even more progressively a.k.a. “true” Climate Science, based upon its mostly rigged Models, given its foundational “tenets”, and, ergo, its Selected Peers is just so much easier and less “inconvenient” = less sceptical – and more lucrative! So what’s wrong with that? [sarc.]

  33. cagw_skeptic99 says:
    July 6, 2010 at 11:00 am
    “[…]I guess I am just not well enough educated in the climate sciences or sophisticated enough to grasp the basis for the concern.”

    Well. It was never my concern; you don’t have to argue with me. But the argument has been brought up all the time by some AGW people. So that’s why MPI got the money for this research, that’s my guess. And i guess it was politicians who greenlighted the check.

  34. Ditto 3: “in other words we have no idea what is going on”. Said this before and I’ll say it again, too many exogenous independent variables, which themselves cannot be predicted, to be capable of predicting future climate. We don’t do that well at predicting weather from day to day other than that which we can SEE coming our way from satellite info and radar.

  35. DonS: July 6, 2010 at 8:43 am
    So, if a brown lawn is watered it will take up more CO2 and get green? Over a temperature range of 45f to 105f? Wow.

    No, first it will green up and *then* take in more CO2.

    Of course, if you’d watered it properly all along, it wouldn’t have browned out in the first place.

  36. It’s great to see that once again that our old friend, Svante Arrhenius comes to the rescue of the climate “scientists”. k = A e^{{-E_a}/{RT}} Similar to his influence on the radiative effects of CO2, Arrhenius’ equation was the first comprehensive estimate of the rate of reaction that applied to ANY chemical reaction, including the reactions of carbon dioxide in the biosphere. To me it is quite incomprehensible that any scientist who got through Chem 101 would not immediately think of this when faced with something like CO2 respiration. The Arrhenius equation, and its later refinements, have been proven to work very reliably over a tremendous range of reactions and temperatures. It seems a pretty obvious place to look when trying to estimate the rates of CO2 uptake and production in the biosphere. Despite the complications of the climate, the basic chemistry wouldn’t change and result in extreme rates of either production or uptake, and, while it’s good to have experimental confirmation, it’s no surprise that the chemical reactions involved vary primarily with temperature and the rate doesn’t miraculously change with increased temperature.

    Good job for the Max Planck scientists to publish this work.

  37. DirkH My apologies if I appear to be arguing with you. I am just (maybe stunned is the right word) at what qualifies for funded research.

    Somewhere I read that a big chunk of the US Government’s stimulus billions was allocated for these research projects. Obviously it must all be spent (or wasted) by the deadline, so anything that claims a relationship to AGW qualifies, no matter how silly it seems to someone like me who pays taxes.

  38. cagw_sceptic99,
    (can I call you #99 for short)
    Don’t forget the peat-bog to coal cycle.

    Well, aren’t we lucky that rainfall isn’t decreasing!

    Comment 3: why isn’t cutting Rainforest a Capitol offense? Has anyone calculated the loss in CO2 sequestration from the rainforest already lost? Does that match the CO2 increase? The timing looks right.

  39. “In most ecosystems, the photosynthesis rate at which plants fix carbon dioxide from the atmosphere changes relatively little as the temperature varies.”

    Doesn’t the growth rate of trees, i.e. tree rings depend directly on the photosynthesis going on in the tree leaves? If this process “changes relatively little as the temperature varies”, then one could conclude that the validity of tree rings as a proxy for temperature is questionable.

    I just finished Bishop Hill’s book, “The Hockey Stick Illusion” and I would highly recommend it. The data selection process (Others may call it cherry-picking) and the contortion of science to create a hockey stick described in this book is mind blowing. I raised the question,
    “Does a tree’s growth rate respond to temperature?” on my website, http://www.socratesparadox.com

  40. We have faith-based beliefs ( = religion ), we have data-based beliefs ( = science ), and now we have computer model-based beliefs ( = ??? ).

    We need a new word for what the climate alarmists are doing. It is not science.

  41. wayne says:
    July 6, 2010 at 10:38 am
    So what caused the great greening of the globe over the last few decades if it’s constant. There was a WUWT post with before and after satellite pictures showing this “greening” effect but I can’t seem to find it in searches. Think it was titled “The greening of the world” or “The greening of the globe”, something like that and was some 5-9 months ago at least. Anyone remember that post?

    CO2 was the factor assumed to be responsible for the greening effect. This paper would tend to reinforce the CO2 effect since there is an apparent lack of temperature response.

  42. pgosselin says:

    I’d say the MPI is in general warmist as a whole, but are ready to change their minds as the science comes in. It is, after all, a worldclass organisation.
    Our sceptic views are also not rock solid. ..

    I know. (The “/sarc” got left out of the post.) The problem with the AGW crowd is their careful avoidance of scientific method – a problem, as this work demonstrates, we won’t see occuring at MPI.

  43. We have faith-based beliefs ( = religion ), we have data-based beliefs ( = science ), and now we have computer model-based beliefs ( = ??? ).

    We need a new word for what the climate alarmists are doing. It is not science.

    How about “fantasy”?

  44. Ed MacAulay says:

    “wayne says:
    July 6, 2010 at 10:38 am
    So what caused the great greening of the globe over the last few decades if it’s constant. There was a WUWT post with before and after satellite pictures showing this “greening” effect but I can’t seem to find it in searches.”

    Could it have been this?

  45. How nice to see some genuine climate science being published for a change! One by one the tenets of CAGW are being destroyed. Just got to get the political motivation weakened and it’s job done.

  46. Smokey says:
    July 6, 2010 at 2:03 pm

    “Could it have been this?”

    Quite amusing to read the caption on the photo about 2/3 down the article. Note that the article was dated 2003.

    “The growth of bristlecone pines in the Inyo Mountains of eastern California is limited by the extreme aridity of their climate, and by cold temperatures in the (relatively) damp spring. Increased rainfall or warmer winters would likely lead to a higher growth rate in these ancient forests. (Photograph Copyright Phillip Greenspun)

  47. cagw_skeptic99 says:
    July 6, 2010 at 9:30 am

    I have a question for someone who understands the land based carbon cycle better than I do.

    Not sure I can lay claim to that, but I’ll add my 2 cents anyway…

    In a tropical forest, the plants take in carbon dioxide, water, and sunlight. They make cellulose and sugar and starch and it looks like a tree or a fern. After a few centuries, does the elevation continue to increase as carbon, in one form or another, builds up? Or does the amount of incoming CO2 settle into equilibrium equal the amount of outgoing CO2 as the dead plant matter decays?

    There is a lot of research that has calculated mature forests do not sequester more CO2, precisely as you discuss. Young forests do, obviously, but exactly what constitutes “young” “mature” etc. is obviously in the eye of the beholder (and the slant of the researcher). What is clear is that re-growth of temperate forests across North America since the mid-late 19th Century is responsible for a very large sequestration of atmospheric CO2 (I’m still trying to re-find this paper – I’ll get it eventually), but the effects may be slowing down now as forest conservation is, perversely, reducing new growth. (Logging in temperate forests in developed countries is almost always follwed by re-planting.)

    There seems to be an assumption here that a mature forest can somehow sequester an essentially infinite amount of matter, or am I missing something?

    I think what you (and I) have a problem with is the terminology – what exactly is meant by “mature” and whether this really is what is happening in tropical forests.

    Another factor that is missed by many people is the inefficiency of trees in fixing CO2 compared to crop plants. Soybean, corn and sugar cane (replacement for tropical forests in South America) fix CO2 at rates far exceeding forests and they are replanted each year. Granted, the recycling of a high percentage of this to atmospheric CO2 is pretty rapid in human and animal food, but this still represents are major sink which I don’t know has been fully accounted for. Many people have focussed on the stocks of agricultural commodities as the only possible sink, but the actual production of crops has massively increased in the last 50 years and the volume of fixed carbon at any one time is significantly greater than the size of these stocks.

    One day (when I get time from my real job) I will try some number crunching to see how this stacks up. In the meantime, don’t be too quick to bemoan loss of old forests as what replaces them may be more valuable.

  48. Thank you Ron Potter.

    To my original point, if you slash and burn a tropical forest, say to grow sugar and make alcohol for motor fuel, you release lots of CO2. When you quit making sugar and the forest returns, then there is lots of new capture of CO2. But on balance, it looks to me like NET nothing, unless the new forest never regains the mass of the old one. If the logs are cut and made into housing, then there is net capture until the houses are demolished, but I still don’t see much net change unless that forest never returns.

    Same with cutting old growth. There are lots of reasons to preserve forests, but I just don’t see a big net difference in atmospheric CO2 unless the cut wood stays out of places where it would decompose. Most of the plant material from crops is decomposed, and even the grain or fruit gets there after some time.

    It is hard to believe that the amounts of CO2 plus or minus from net land vegetation changes really matters much when compared to the existing CO2 dissolved in the ocean and the (relatively tiny) amount present in the atmosphere. Net new CO2 from burning fossil fuels would matter, but it just doesn’t seem to me that the land based vegetation absorbs enough to matter in global calculations over decades or centuries.

  49. In all time my reading about photosynthesis and Internet searches, I have seen only 1 paper about plant root systems, O2, H2O in CO2 out. I dont believe the CO2 is kept around the root sytem otherwise we would have Forests looking like Horseshoe Lake in Mammoth Ca.. Does filter upward and lie around the base of the plant, or sideways, or downward? I would love to know.

  50. “”” Enneagram says:
    July 6, 2010 at 9:04 am
    Do these guys, no matter how important and famous their institutions are (or rather were), prepare their breakfasts using hairdryers?. How does the air heat the oceans?
    (BTW don’t forget hairdryers must be plugged into a power source). “””

    Just remember those laboratory experiments that demonstrate that the air sample with the higher CO2 content reaches a higher Temperature than the air sample with less CO2; when both are irradiated by a heat lamp (taking good care of course that the heat lamp energy doesn’t fall directly on the thermometers).

    But just remember that per Trenberth’s cartoon (official NOAA chaff) diagram of the earth’s energy budget; the average rate of LWIR emission from the surface is 390 W/m^2 corresponding the the BB total emittance from a surface at the mean global temperature of 15 deg C (288 Kelvins).

    So next time you do that lab experiment to demonstrate the effect of CO2 on atmospheric warming; you have to use something like a brick at 15 deg C as your LWIR source; there are very few actual “heat lamp sources” pointing up from the average surface of the earth; and the human body does not register 10.1 micron peaked LWIR as “heat”; we cannot even sense it at all (with human sensors). Try holding up a nice red brick cooled down to 15 deg C up close to your delicate face, and feel the “heat” just pouring from that brick. Just imagine how much that is going to heat the atmosphere, and in turn just how much higher (Temperature) the surface is going to get from that LWIR heat returned (partly) from the atmosphere.

    Yeah; now pull my other leg.

  51. I gather that the paper is suggesting that a 10 degrees ( no units … assume C ) temperature rise gives a global average 140% increase in the rate of CO2 uptake. That is, as we would have hoped, the earth has a nice negative feedback in place.

    Man’s CO2 contribution to the atmosphere is about 0.8% of the total, the rest being natural sources (from the IPCC’s carbon cycle diagram). On the above basis, a temperature rise of around 0.2 deg C should be enough to balance man’s added CO2 contribution to the atmosphere (it’s a log relationship of course, not linear)

    The above ignors the effects of temperature on ocean outgassing etc etc etc …

    Am I missing something here ?

  52. Bruce of Newcastle says:
    July 6, 2010 at 5:10 pm

    Mushrooms that normally get only 2-3″ high are found next to a freeway 12-14″ high.
    Almost forgot about that one, but your post reminded me.
    It’s the c02 exhaust.

  53. Well that’s all well and good; I’m glad that someone is willing to pay good money to find out just how the biosphere takes up carbon.

    It would be nice if someone would spend a similar amount of money to show that in any case; carbon doesn’t have much to do with earth’s climate; well as far as causing it; that is.

    IT’S THE WATER !

  54. Smokey says:
    July 6, 2010 at 2:03 pm
    Could it have been this?

    Close Smokey, but this was two side by side satellite photos a few to a decade apart at the same time of year. The reason I remember that post (it could possibly been some other article from another source, I thought here) is that the difference was so striking. Well, if you ever come across on it, take a look, it makes you wonder how some of these claims are made when the photos say the opposite.

    And Ed, I think it was more all three to some degree even though they now say temperature has little to do with general growth (think I’ll wait for some confirmation on that one).

  55. The conclusion seems to be that plants will grow well and fix carbon dioxide even when it is hot as long as there is sufficient water! Actually I, and every other person with a garden could have told them that without spending any research money.

  56. Both of the above studies (and others) seem to assume that loss of atmospheric CO2 is due to the biosphere alone. And maybe that is correct. But I note that the point of fastest CO2 removal is approximately July 1, summer in the NH, but winter in the SH. Does the SH winter cool the oceans there enough to absorb significant CO2?

  57. @DirkH says:
    July 6, 2010 at 10:22 am

    “…This research beautifully destroys one foundation of the catastrophist’s fantasies: That an increase in temperature will reduce the photosynthetic capabilities of vegetation severely, leading to a much higher accumulation of CO2….”

    If they thought that, then they are not paying attention to the earth and its historical legacy. The Mississippian and Pennsylvanian periods (aptly, the Carboniferous period) apparently (cannot be sure, but the research strongly says so) featured high temperatures (~6 ºC warmer) and much higher CO2 content (+2000 ppm). Massive deposits of coal (dead trees and ferns stacked one upon another for millions of years) formed during those times.

    Similarly, the rock formations from the Cambrian (~600 mybp) through the Permian (~250 mybp) are dominated by carbonate (limestone and dolomite) rocks – reefs, associated fore and back reef carbonates, and platform carbonates – massive deposits of CO2-bearing rocks. Trillions of tons of CO2-bearing rocks! Although CO2 exhibits reverse solubility (its solubility decreases as temperature rises, as opposed to, say, salt), there was so much of it in the atmosphere that the deposition of limestone – calcium carbonate CaCO3 – was forced.

    Today we’re in an historical dearth of CO2. Yet these plants that clothe the earth, and various critters that swim in the seas, and just about everything else on this planet, evolved in a time of greater warmth and CO2 abundance. I would say that the last 20 million years or more have been tough on the planet’s flora and fauna – sort of like a summer in San Francisco.

    And to extend that, in the lip-flapping about “sustainability”: what period do we want to sustain? Vast numbers of critters lived and evolved in much warmer and CO2-rich times than our present time. Should we sustain that? Woolly mammoths were perfectly adapted to a time of much greater cold (and low CO2), but died out when that changed to the interglacial warmth. Should we sustain that fauna and flora? Or, maybe, should we accept that the earth is ever-changing, and just insure that we aren’t the agency of mass changes (like the slaughter of the buffalo and the passenger pigeons?)

  58. Markus Reichstein adds: “Particularly alarmist scenarios for the feedback between global warming and ecosystem respiration thus prove to be unrealistic.”

    There, case closed. Joe Romm, get out.

  59. jorgekafkazar says:
    July 6, 2010 at 7:03 pm

    Both of the above studies (and others) seem to assume that loss of atmospheric CO2 is due to the biosphere alone. And maybe that is correct. But I note that the point of fastest CO2 removal is approximately July 1, summer in the NH, but winter in the SH. Does the SH winter cool the oceans there enough to absorb significant CO2?

    I read on this site that the reason is that there is so much more land area in the NH than the SH, which explains the out-of-balance CO2 removal pattern.

  60. 6. Particularly alarmist scenarios for the feedback between global warming and ecosystem respiration thus prove to be unrealistic.”

    That would seem to be a sure way of ensuring the grant money stops and also to have groups of scientists gang up to ensure you will not be allowed to publish future work in any “reputable” journals! /Sarc off.

    Real empirical experiments! Whatever next!

  61. When our climate scientists realise that adding all the two and four legged animals together, we are but a pimple on a bum the size of the moon. The huge volume of biological life on our world is insects, germs, enzymes,plankton, etc, these busy little devils are burying or converting CO2. These little guys out weigh us thousands to one more CO2 = more food for them= more productive soil and ocean= a better world.

    This is a win win situation, more warming even better. Why are these people so anti a better world. This study at least shows a break through in common sense.

  62. @ PJB – “We have faith-based beliefs ( = religion ), we have data-based beliefs ( = science ), and now we have computer model-based beliefs ( = ??? ).”

    Hocus Pocus?
    Post modern dogs dangles?
    Consensus science?

  63. rbateman says:
    July 6, 2010 at 5:27 pm

    Mushrooms … 12-14″ high … It’s the c02 exhaust.

    Hmmm… Mushrooms do not photosynthesize – CO2 is NOT mushroom food.

  64. ““We were surprised to find that the primary production in the tropics is not so strongly dependent on the amount of rain,” says Markus Reichstein.”

    Amazon anyone?

    “With a novel combination of observations and modeling, they estimate the total amount of carbon that the world’s plant life inhales annually is 123 billion metric tons.”

    As Lord Monckton would say “measure it.”

    “2. The respiration of the ecosystems, when flora and fauna release carbon dioxide again, also increases to a lesser extent than has recently often been assumed when the temperature rises.”

    Couple this with: CO2 amplification is less than we thought
    “Ensemble reconstruction constraints on the global carbon cycle sensitivity to climate”
    Nature: December 2009

    /sarc on/
    The science becomes more and more settled as time rolls on.
    /sarc off
    IMHO it is the above and many other reasons known and unknown that accounts for the continual failure of the climate models.

  65. @Bill Tuttle: Don’t water the lawn at all. Here in Montana water comes concurrently with an event known as “Spring”.

  66. DonS: July 7, 2010 at 6:20 am
    @Bill Tuttle: Don’t water the lawn at all. Here in Montana water comes concurrently with an event known as “Spring”.

    What a coincidence — our township snow removal plan is called “Spring”…!

  67. JimF – don’t be too ready to repeat the conventional wisdom about the fate of the buffalo and the passenger pigeon.

    Charles Mann’s ‘1491’ (http://www.amazon.com/1491-Revelations-Americas-Before-Columbus/dp/1400032059), quoted by Stewart Brand (the Whole earth Catalog guy) in ‘Whole Earth Discipline’ (http://www.amazon.com/Whole-Earth-Discipline-Ecopragmatist-Manifesto/dp/0670021210), notes that the Americas were extensively gardened/tended by their original inhabitants. What did for the buffalo (almost) and the passenger pigeons (entirely) was the removal of most of their human competitors for food by the effect of Western microbes. The passenger pigeon population overshot, then crashed.

    As the delicious quote in Mann has it: “Faced with an ecological problem, the Indians fixed it. Rather than adapt to Nature, they created it. They were in the midst of terraforming the Amazon when Columbus showed up and ruined everything”.

  68. I’m still not seeing a human influence in the CO2 levels measured at Mauna Loa. The US economy came to a crashing halt starting in December of 2007 or the Global Recession of 2008. The US uses a greater volume of CO2 producing fossil fuels than any other nation (including China – which exports most of its production to the US). Still – the Mauna Loa CO2 graph only shows seasonal variations.

    What type of economy limiting measures (and/or ‘Green Jobs’ programs) will have to be enacted to show a response in the CO2 measurements?

  69. Cris Streetzel

    I think the point you take stuffs tree rings as thermometers. Mann, Jones, Briffa and all the other shysters can be put on pensions, to the serious financial relief of the rest of us.

  70. cagw_skeptic99

    There must be an equilibrium between C uptake and C loss through transpiration, decay, soil storage etc. If that were not so, then by the Law of Conservation of Mass, the biomass of the trees/ferns/whatever would increase indefinitely.

  71. testing

    “There must be an equilibrium between C uptake and C loss through transpiration, decay, soil storage etc. If that were not so, then by the Law of Conservation of Mass, the biomass of the trees/ferns/whatever would increase indefinitely.”

    [Note: There is a “Test” link on the masthead menu. Also, I fixed your blockquote HTML. No need to use ‘cite’; blockquote in arrow brackets is enough. ~dbs, mod.]

  72. Climate models only recently began to include global carbon cycles. So such findings don’t effect the decades of previous simulations which have warned us of trouble ahead.

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